Correct procedure for chain tensioner mounting

[Faber32]

Hi everyone. I'm about to do a new head gasket and I have a doubt about the mounting of the tensioner.  Is it correct that I have to unscrew the central hex screw (red arrow in the pic) to get access to a flat screwdriver screw that has to be turned to make the piston retract before installing it?
If I understood correctly, if I mount it as it is, i.e. with the piston all the way out, I'd damage the timing system.
Thank you for help :-)

[Iahawk]

mine was clearly detailed in my service manual (for S200)...there was a certain procedure to follow but I can't recall as it's been a few years. Do you own a service manual for your scoot? 

[Faber32]

Thank you. Yes I have the official service manual but it's not explained anywhere. Maybe I should check your service manual at this point.
From what I've learnt on Youtube, there are two kinds of tensioners. The ones with a long spring that comes off once you remove the central screw, and the other ones with a flat screw deep inside tu be turned clockwise. I suppose mine is of the second kind but I have no confirmation about that

[Ruffus]

If you have the type (see pic) YES, flat screwdriver, "unlock", push up, and "lock".

If you have "hexagonal" type, screw out, springcoil out, then assamble on the chain

[Faber32]

Thanks Ruffus, very useful. I have the hex kind, so with a spring. Now I know!